參數(shù)資料
型號(hào)： MAX15009
廠商： Maxim Integrated Products, Inc.
英文描述： Automotive 300mA LDO Regulators with Switched Output and Overvoltage Protector
中文描述： 用于汽車電子的300mA LDO穩(wěn)壓器，提供可切換輸出和過(guò)壓保護(hù)
文件頁(yè)數(shù)： 14/23頁(yè)
文件大?。?/td> 479K
代理商： MAX15009
M
Automotive 300mA LDO Regulators with
Switched Output and Overvoltage Protector
14
______________________________________________________________________________________
off the external MOSFET, disconnecting the power
source from the load. In this configuration, the voltage
at the source of the MOSFET is not monitored. When
the voltage at FB_PROT decreases below the overvolt-
age threshold, the MAX15009 raises the voltage at
GATE, reconnecting the load to the power source.
Overvoltage-Limiter Mode (MAX15009 Only)
When operating in overvoltage-limiter mode, the feed-
back path consists of SOURCE, FB_PROT’s internal
comparator, the internal gate charge pump/gate pull-
down, and the external n-channel MOSFET (Figure 2).
This configuration results in the external MOSFET oper-
ating as a hysteretic voltage regulator.
During normal operation, GATE is enhanced 8.1V above
V
IN
. The external MOSFET source voltage is monitored
through a resistive voltage-divider between SOURCE
and FB_PROT. When V
SOURCE
exceeds the adjustable
overvoltage threshold, an internal pulldown switch
discharges the gate voltage and quickly turns the
MOSFET off. Consequently, the source voltage begins
to fall. The V
SOURCE
fall time is dependent on the MOS-
FET’s gate charge, the internal charge-pump current,
the output load, and any load capacitance at SOURCE.
When the voltage at FB_PROT is below the overvoltage
threshold by an amount equal to the hysteresis, the
charge pump restarts and turns the MOSFET back on.
In this way, the OVP controller attempts to regulate
V
SOURCE
around the overvoltage threshold. SOURCE
remains high during overvoltage transients and the
MOSFET continues to conduct during an overvoltage
event. The hysteresis of the FB_PROT comparator and
the gate turn-on delay force the external MOSFET to
operate in a switched on/off sequence during an over-
voltage event.
Exercise caution when operating the MAX15009 in volt-
age-limiting mode for long durations. Care must be
taken against prolonged or repeated exposure to over-
voltage events while delivering large amounts of load
current as the power dissipation in the external MOS-
FET may be high under these conditions. To prevent
damage to the MOSFET, implement proper heatsinking.
The capacitor tied between SOURCE and ground may
also be damaged if the ripple current rating for the
capacitor is exceeded.
As the transient voltage decreases, the voltage at
SOURCE falls. For fast-rising transients and very large
MOSFETs, connect an additional capacitor from GATE
to PGND. This capacitor acts as a voltage-divider work-
ing against the MOSFET’s drain-to-gate capacitance. If
using a very low gate charge MOSFET, additional
capacitance from GATE to ground might be required to
reduce the switching frequency.
Control Logic
The MAX15009/MAX15011 LDO features two logic
inputs, EN_LDO and
HOLD
, making these devices suit-
able for automotive applications. For example, when
the ignition key signal drives EN_LDO high, the regula-
tor turns on and remains on even if EN_LDO goes low,
as long as
HOLD
is forced low and stays low after initial
regulator power-up. In this state, releasing
HOLD
turns
the regulator output (OUT_LDO) off. This feature makes
it possible to implement a self-holding circuit without
external components. Forcing EN_LDO low and
HOLD
high (or unconnected) places the regulator into shut-
down mode, reducing the supply current to less than
16μA. Table 1 shows the state of OUT_LDO with
respect to EN_LDO and
HOLD
. Leave
HOLD
uncon-
nected or connect directly to OUT_LDO to allow the
EN_LDO input to act as a standard on/off logic input for
the regulator.
IN
V
IN
FB_PROT
SGND
GATE
SOURCE
PROTECTOR
OUTPUT
MAX15009
Figure 2. Overvoltage Limiter (MAX15009)
相關(guān)PDF資料
PDF描述
MAX15011 Automotive 300mA LDO Regulators with Switched Output and Overvoltage Protector
MAX15024 Single/Dual, 16ns, High Sink/Source Current Gate Drivers
MAX15025 Single/Dual, 16ns, High Sink/Source Current Gate Drivers
MAX1513ETP TFT-LCD Power-Supply Controllers
MAX1514ETP TFT-LCD Power-Supply Controllers
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
MAX15009ATJ+ 功能描述:低壓差穩(wěn)壓器 - LDO Automotive 300mA w/Switched Output RoHS:否 制造商:Texas Instruments 最大輸入電壓:36 V 輸出電壓:1.4 V to 20.5 V 回動(dòng)電壓（最大值）:307 mV 輸出電流:1 A 負(fù)載調(diào)節(jié):0.3 % 輸出端數(shù)量: 輸出類型:Fixed 最大工作溫度:+ 125 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:VQFN-20
MAX15009ATJ+T 功能描述:低壓差穩(wěn)壓器 - LDO Automotive 300mA w/Switched Output RoHS:否 制造商:Texas Instruments 最大輸入電壓:36 V 輸出電壓:1.4 V to 20.5 V 回動(dòng)電壓（最大值）:307 mV 輸出電流:1 A 負(fù)載調(diào)節(jié):0.3 % 輸出端數(shù)量: 輸出類型:Fixed 最大工作溫度:+ 125 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:VQFN-20
MAX15009ATN+ 功能描述:低壓差穩(wěn)壓器 - LDO Automotive 300mA w/Switched Output RoHS:否 制造商:Texas Instruments 最大輸入電壓:36 V 輸出電壓:1.4 V to 20.5 V 回動(dòng)電壓（最大值）:307 mV 輸出電流:1 A 負(fù)載調(diào)節(jié):0.3 % 輸出端數(shù)量: 輸出類型:Fixed 最大工作溫度:+ 125 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:VQFN-20
MAX15009ATN+T 功能描述:低壓差穩(wěn)壓器 - LDO Automotive 300mA w/Switched Output RoHS:否 制造商:Texas Instruments 最大輸入電壓:36 V 輸出電壓:1.4 V to 20.5 V 回動(dòng)電壓（最大值）:307 mV 輸出電流:1 A 負(fù)載調(diào)節(jié):0.3 % 輸出端數(shù)量: 輸出類型:Fixed 最大工作溫度:+ 125 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:VQFN-20
MAX1500VETN 制造商:Rochester Electronics LLC 功能描述: 制造商:Maxim Integrated Products 功能描述:
發(fā)布緊急采購(gòu)，3分鐘左右您將得到回復(fù)。

采購(gòu)需求

(若只采購(gòu)一條型號(hào)，填寫(xiě)一行即可)

發(fā)布成功！您可以繼續(xù)發(fā)布采購(gòu)。也可以進(jìn)入我的后臺(tái)，查看報(bào)價(jià)

發(fā)布成功！您可以繼續(xù)發(fā)布采購(gòu)。也可以進(jìn)入我的后臺(tái)，查看報(bào)價(jià)

*型號(hào) *數(shù)量 廠商 批號(hào) 封裝
添加更多采購(gòu)

我的聯(lián)系方式

*
*
*